R&D (FilterCavity)
EleonoraCapocasa - 20:22, Wednesday 27 May 2020 (2086)
frequency independent squeezing recovery

Yuhang, Eleonora

We check the power at different points on the bench and compared with nominal values. We only had to realign IRMC. After re-alignment its trasmission is above 80% (much larger than GRMC)

Here the current values for reference:

GR power before green EOM 280mW
GR power before AOM 51 mW
GR power before MZ 220mW
GR power after AOM 16 mW
GR before GRMC 48 mW
GR after GRMC 93 mW
GR into the viewport 14mW
GR pump before entering OPO 19 mW
IR power before IRMC 2.2mW
IRMC transmission 1.8mW

Then we adjust the setup to measure FIS. We recovered the alignment of homodyne and measured the squeezing, finding values similar as before (~ 6 dB). Plots will be updated soon. We remarked that the CC1 loop is not stable and keeps unlocking. We plan to repace soon the GR phase shifter, hoping this will impove the situation.

We also checked the alignement of BAB into FC. It was still fairly good.